1. Field
Apparatuses consistent with one or more exemplary embodiments relate to a structure of a turbine impeller including a blade with a squealer tip for preventing thermal damage and for featuring high efficiency.
2. Description of the Related Art
A turbine is a device for producing power by using an energy generated as a high temperature and high pressure fluid flows in the turbine and expands. In the related art, the turbine includes one or more turbine impellers. Each turbine impeller includes a rotor located at the center and a plurality of blades extending in a long shape from a surface of the rotor. The rotor and the blades that are formed as a single body is accommodated in a shroud. The single body of the rotor and the blades rotates, and produces power.
Particularly, in case of an axial turbine, a fluid flows in a direction almost parallel to the rotating axis of a turbine impeller, and the fluid flowed into the turbine flows and contacts blades, thereby rotating the turbine impeller. Here, an end of a blade is located at a predetermined distance apart from the shroud to prevent the blade from being damaged and to allow smooth revolution. However, the fluid passing through the gap between the end of the blade and the shroud cannot contribute the production of energy via revolution of the turbine impeller at all. Therefore, the fluidic energy of the fluid through gap is wasted.
To prevent deterioration of efficiency of a turbine due to the fluid leaked through such a gap, a squealer tip is formed at an end of a blade close to a shroud.
The squealer tip is a protrusion which is formed at an end of a blade having a airfoil-like cross-sectional shape and has a predetermined height, where an airfoil-like groove is formed at an end of a blade having a squealer tip.